One Rule
by xKaseix
Summary: The golden rule in Happy Tree High School: Never, in any way, mess with Flippy, or imply that you might like him in a romantic sense. Unfortunately for his many admirers, he had a possessive brother. Main: Evil/FliqpyxFlippy twincest. Warnings and other pairings inside. Evil/Fliqpy and Flippy goodness.


**Verse: Human High School!AU**

**Warnings: Implied/mentioned character death; twincest; minor language amd moderate Flaky!bashing on Evil's side.**

**Pairings: Evil/FliqpyxFlippy (twincest in this verse), ShiftyxLifty, one-sided FlakyxFlippy.**

**Please enjoy. :)**

_One Rule_

In Happy Tree High School, there was one golden rule to follow: Never, in any way, imply that you like Flippy.

In fact, most would advise to avoid the green-haired, military-obsessed teen altogether. The greedy Shifty-Lifty duo were exclusive in having any association with him, and that was limited to pickpocketing him when they thought it was relatively safe to do so.

You see, Flippy had a twin brother, one that wasn't quite...sane, and more than a little violent. This sibling was practically a clone of the younger, there being only two noticeable differentiations. The first being predatory golden eyes instead of kind emerald, and the second bone-cutting teeth sharpened by the twin himself. Both of them wore the exact same outfit: black t-shirt, forest green army jacket and pants, combat boots, black fingerless gloves, and realistic dog tags.

Evil was obsessively possessive of his copy. No one could speak to, harm, or assist Flippy barring Evil. He was the time that needed his counterpart to be fully dependent on him for everything. Anyone with a brain could tell that the love between them was not purely platonic, at least on one side, though few dared think about it.

Truly, Shifty and Lifty were the only ones that knew the depths of the relationship. There were few things they did not know as they were always watching the town's residents, waiting for glimpses of precious valuables and bits of information worth selling. Observation was their greatest talent.

For example, most wouldn't know that while Flippy was the saner and sympathetic of the two, he could go into possessive streaks of his own, and was often amused by the other's homicidal rages, though he didn't approve of them. If it was someone he cared about, regardless of the older twin's reasoning, he would instigate a brutal fight between the two (often taking out the entire town in the meantime) and then was cold to the elder for days. The best way to ensure survival was to get on the sweeter's good side, through the employment of cute animals and tea. Lifty and Shifty and bought their protection with a kitten.

"Is she an _idiot_?" Lifty asked rhetorically, aghast. They were sitting on the steps outside the high school, looking for a new target after having gutted Mr. Russel's house boat last night.

Shifty raised an eyebrow at his twin-slash-lover, following his gaze towards the nervous redheaded girl standing in the shade of a nearby oak tree, twiddling her fingers as she whispered something to the guy she stood in front of. She was an alright-looking girl: long crimson locks, hazel eyes, pale skin, long legs, modest fashion sense. Her personality wasn't too bad, but her emotional fragility made others anxious around her, trying not to set her off. She had some serious _lungs_, perfect for that distinct scream of hers.

It took him a moment to comprehend what Lifty was saying. The guy Flaky was talking to had _green_ hair. Not the dark-almost-black green hair both of them had, but _sea foam green_. He doubted she would be as calm as she was if that was Evil in front of her, which left...

Quickly he glanced around, freezing when he saw _another _head of sea foam green locks. This figure was facing them, so they could clearly see the golden eyes glinting with _jealousy, anger, hatred_, and the snarl displaying those too-sharp teeth. Shifty nearly shivered at the furious facial expression.

"Apparently so," he finally answered Lifty, who shook his head helplessly. The younger then turned his attention to Mr. Lumpy, watching him warily in case he caused _another_ freak, very fatal, accident.

In Happy Tree Town, people died regularly, though they always managed to appear within the week. Physically, they were in perfect shape. Mentally, they were scarred with the memory of those last moments. Lifty and Shifty were among the ones who died most often, seeing as their heists had a tendency to go all wrong (this was when Mr. Lumpy (who doubled as an incompetent police officer) and Splendid (idiotic wannabe superhero) got themselves involved).

However, out of all those painful, tragic experiences, their temporary ends dealt to them by Evil, the one time they had foolishly crossed him by teasing Flippy about the possibility of Splendid liking him, were the most _horrible. _It was what made them give Flippy the free cat in the first place, just for insurance. It was also when they had confirmed that Evil and Flippy were, in fact, together in the romantic sense.

Unable to suppress this next shudder, Shifty eased closer to Lifty, who smiled in response and met him half-way. "Never gets easier, does it?" he asked.

Indulging in a moment of utter _fluff_ hesitantly, Shifty replied, "It does every time I come back and find you waiting at home with that hopeful-but-hopeless look on your face. And then you smile at me and tackle me to the ground and I smile back."

Lifty practically beamed up at him.

Glancing around to be sure no one was watching, he gave the other a light peck on the cheek. Then he turned back to watching their classmates and teachers as they arrived, rare moment over but both of them wholly satisfied.

Evil, however, was not the least bit happy. He had left his twin on the bench in the school courtyard for one goddamned moment to give Mr. Russel his overdue paper, then returned to find that yes, he had moved, and yes, he was talking to someone else. Not just any _someone else_, but a female, and one that Evil knew had had a crush on the sweeter brother since childhood. Who was it? That bitch Flaky.

Taking a deep breath, he tried to calm himself. And failed. Horribly. Okay, try to be logical about this, evaluate the enemy...Flaky was an idiot, but she had strong self-preservation instincts, she wouldn't approach Flippy, knowing it might incite his wrath, unless she had absolutely no choice.

There were issues with that theory. She seemed much too calm and they were laughing too much for them to be talking about a school project or anything so mundane.

Flippy was the one uncomfortable, and as adorable as it was, it set his teeth on edge that someone was making him uneasy to the point it was actually showing. He always had superb control of his emotions, and could act his way through any situation be it legal, social, or what have you, without betraying anything. Sure, he usually had his overprotective brother at his shoulder, but the few times Evil left him for the purpose of watching him from behind a tree, he seemed much the same, if a little lonely. The only times he let all his barriers down was when they were at home, just the two of them (their father had died in combat when they were toddlers, and sickness took Mom away just last year).

He was violently shoved back into the present when the redhead moved a little closer to his Flippy. Really, it was only an inch, and could have been for the purpose of hearing him better, but it had the rest of Evil's muscles tensing in preparation.

_Breathe. You promised Flippy you would stop killing people at school. _

Small promise, really, seeing as he could easily wait until the victim left school grounds and _then_ slit their throat.

Now, though, he was seriously regretting it. He honestly didn't see how it mattered. Lumpy was the town's entire legal system, and he was terrified of Evil, refused to so much as set up an investigation into one of his many murders, much less charge him with it.

Carefully, he sneaked passed the two and to the side, coming up nearby but blocked from view by the towering oak tree. Flippy was too distracted to notice. Leaning back against the tree, he listened.

Laughing.

"Yeah, I heard that. Poor Giggles." That was Flippy's voice.

"Yeah, but it turned out alright. Her and Cuddles are cute together, I hope they last."

"Seem to match up pretty well, huh?"

"Yes," she squeaked, and Evil could _see _the blush blossoming on porcelain cheeks. Just what was she getting at? She couldn't really...?

"Hm...Very happy for them..."

"So, um, do like dogs?" Weird question...

"Yeah, a bit. Evil has one. I'm more of a cat person, you know?" Yeah, and you can keep that demonic furbag you call a 'cat'.

"Y-yeah! Same here."

"I have one, she's a domestic shorthair. Her name's Oreo, but Evil usually calls her Hellspawn, so she's kind of confused on which one's her actual name...She's nice, really, just hyperactive. Aren't all cats hyper?" Yes, but most of them know after the first time that breaking vases and dishes were bad things to do. Oh, and that shredding shoe strings made Evil _very_ mad.

This conversation was almost painfully awkward.

Hey, Flippy, remember the time she _stabbed you in the __**eye**_ with a shard of _fucking __**glass**_ because she thought you were me? Ever thought what would have happened if she hadn't realized you were _you_, or that it _had_ been me?

Snarling, he decided he'd had enough of this bullshit. Stepping out from behind the tree, he came up just to the back of Flippy. Flaky gasped in surprise and fear, stumbling back a few steps. Flippy, though, looked relieved when he turned and saw him there.

"Hey, Evil, what took you so long?" he asked, smiling the brightest smile to ever fucking exist up at him. Don't look too closely or you'll go blind.

"Someone gave Mr. Mole a sharp instrument again so I had to dodge around that area. Took some time," he lied effortlessly. "What's going on here?"

"Oh, Cuddles finally got the nerve to ask Giggles out, I'll tell you the funny details later. And then Flaky and I were just talking about Hellspawn," pointed glare, "and his kitten antics."

"I see. At what point were you planning on asking my_ very _taken boyfriend out, bitch?"

Flaky looked absolutely flabbergasted, while Flippy seemed a mix between amusement and exasperation.

"I wasn't..."

"You know I was going to say no when she did get to that point, Evil. No need to be so hostile, you might end up breaking your promise," Flippy reminded, allowing a secretive smirk.

Evil returned it, resolving to ignore the redhead for the time being. Unfortunately, that meant he had the whole day to wait and be paranoid before he could deal out the lesson.

Flippy must have been following his train of thought because he gave a sigh, latched onto the frozen girl's arm, and began pulling her towards the gate. "Eh, nothing's happening at school today anyway, right Flaky? Let's skip today and continue our conversation outside."

Evil smirked at this idea, knowing very well where this was going.

Flippy understood that Evil had to enforce the golden rule all must follow.

Never, in any way, imply that you like Flippy. It was best to avoid both brothers overall, really.

Shifty and Lifty watched them go, relieved not to be in her place and smirking at the thought of raiding her house in her absense.

**A/N: Well, that's all this time! Wanted to leave Flaky's torture and death for your wicked imaginations, plus I didn't want to traumatize Flaky fans. Lots of exposition, little action. Hope you were alright with that for this instance.**

**Please review!**


End file.
